How much like school should 'biotechnology camp' be?

I am teaching a camp to rising 9th graders in biotechnology for one week of mornings. we will extract their DNA, do pcr, run a gel. I figure these kids chose to sign up for a technology camp and will want to do and learn about science. I have made sure to plan for some time each day of arts kinds of things so they can sit around and chat. There will also be breaks of course. There won't be any tests or quizzes, but I do have lessons planned. Is this too much? Should I try to organize things like frisbee or just figure they can pick up any unplanned fun thing in the breaks. there will be 12 of them, slightly more boys then girls.